Sandia modular robot hand brings a delicate touch to bomb disposal

The Sandia Hand combines high dexterity with very low production costs (Photo: Sandia Laboratories)

Robots have been used routinely in bomb disposal for over forty years. Unfortunately, the standard way that robots deal with bombs is to blow them up. This removes the threat, but it also destroys valuable evidence that could lead to catching the bomb makers. Sandia National Laboratories of Albuquerque, New Mexico has developed a new robot hand that is not only delicate enough to disarm a bomb rather than detonating it, but is relatively inexpensive and can even mend itself.

Bomb disposal is delicate work and the benefits of a dexterous, durable hand that could disarm IEDs and similar threats rather than exploding them is clear. Unfortunately, robot hands aren’t cheap. The current going price is more than US$250,000, so the cost has to come down drastically if such robots are to be made widely available.

Funded by Defense Advanced Research Projects Agency (DARPA), Sandia Laboratories has developed the Sandia Hand - a robot hand that combines a high degree of dexterity with a low price tag. Sandia did this by making the Sandia Hand modular. Instead of a single construct, the hand consists of a palm with attachment points around it for the fingers.

The fingers are self-contained modules that attach magnetically to the palm. These can be quickly plugged in, added or swapped. The fingers and the palm are coated with a gel-like plastic that grips objects like human skin does, so there’s less chance of dropping screws and other small, slippery objects. They can also bend backwards in a manner that is alarming to see the first time, but which provides for much greater flexibility. The fingers don’t even need to be fingers - they can also be a variety of tools, such as flashlights, screwdrivers or cameras.

The modular design makes the hand very easy to repair because rather than breaking if the hand bumps into something, the fingers are designed to snap off at a magnetic point of contact. This means that fixing the hand is simply a matter of popping the errant finger back on. Providing the hand still has enough fingers left, it can even manage this itself.

The hand uses a teleoperator system with the hand control in the form of a high-tech glove. The use of the glove by the operator is very intuitive, which means that even novices can operate the hand easily.

In addition to its other advances, the hand is also very cost effective. Where robot hands normally cost over US$250,000, the Sandia Hand is a bargain. “The Sandia Hand has 12 degrees of freedom, and is estimated to retail for about US$800 per degree of freedom - US$10,000 total - in low-volume production. This 90 percent cost reduction is really a breakthrough,” said Principal investigator Curt Salisbury.

All this may be a potential boon for bomb disposal teams, but Sandia senior manager Philip Heermann regards the Sandia Hand as a “disruptive technology” on a par with the microchip. “Computers, calculators and cell phones became part of daily life and drastically changed how we do things when the price became affordable,” Heermann said. “This hand has the same potential, especially given that high-volume production can further reduce the cost.”